Electrolytic apparatus and process



M. M. MERRITT.

ELECTROLYTIC APPARATUS AND PROCESS.

APPLICATION FILED NOV. 2. 1917.

1,381,882, Patnted June 14,1921.

MATTHEW M. MERRITT, OE SOUTH MIDDLETON, IVLASSACHUSETTS, ASSIGNOR T COPPER PRODUCTS COMPANY, 0E 0F MAINE.

BOSTON, MASSACHUSETTS, A. CORPORATJEQN J ELECTROLYTIC APPARATUS AND PROCESS.

menses. I

Specification of Letters Patent.

Patented June it, 1921..

Application filed November 2, 1917. Serial No. 199,812.

To all whom it may concern:

Be it known that I, MATTHEW M. Mnnnrrr, a citizen of the United States, and a resident of South Middleton, county of Essex, Com' ing drawings, is a specification, like characters on the drawings representing like parts.

This invention pertains to electrolytic apparatus and processes, and more particularly, though not exclusively, to apparatus and processes for use in connection with the electrolytic deposit of copper on extending cathode surfaces such as drums in connection with the manufacture of electrolytic sheet copper.

In the drawings which show one illustrative embodiment of my invention:

Figure 1 shows a rotatable drum and tank for containing the electrolyte;

Fig; 2 is a section on the line 22 of Fig. l, and shows a detail of a preferred form of anode for use in connection with my invention and heavily charged I trolyte.

Fig. 3 shows a detail of aportion of the preferred form of anode containing apparatus shown in Fig' 2. I have found by extensive experiment that in the electrolytic deposit of copper or other metals, the electrolyte attacks and removes metal from the edges of the anode much more rapidly than from the other portions thereof. Thus where extended sheets are utilized as anodes, the electrolyte is much more with. ions traveling toward the cathode at portions of the bath adjacent the edges of the anode sheets. also found that the ions. in their path through the electrolyte approximate travel the shortest distance from any given point on the anode to the adjacent point on the cathode. Therefore where copper sheets or other extended metallic deposits are formed by electrolysis, a considerable variation in the thickness of the deposited sheet exists, the thicker portions of the deposited sheets being adjacent the edges thereof.

I have found that a deposited cathode sheet may be formed of much more uniform thickness by utilizing an anode presenting a large number of edges to the action of the elec- I may conveniently present the ex 1 have in their tended surface desired by cutting up or otherwise dividing the anode material, or by the utilization of anode material presenting a maximum amount of surface-and a maximum number of edges. Such material may, if desired, take the form of copper Wire, tubing, trimmings, broken castings and the like, which can be thus avoiding the expense of cutting up the more usual anode materials.

I have found that such materials may be very conveniently utilized by providing a screen or cathode retainer therefor inter posed between the anode material and the cathode, this screen or retainer preferably being located relatively close to the surface of the cathode and preferably being wood or other non-conductive material and perforated by staggered holes therethrough so that the passage of ions through the bath to the cathode will not be retarded to a greater extent at one portion of the cathode than at other portions thereof.

In the preferred embodiment of my invention selected for illustrative purposes, the rotating cathode a is immersed about onethird in the electrolyte a tank 5. vided,

wooden which is contained in purchased in that form,

staggered perforations therethrough, as best I shown in Fig. 3, which shows portions of two of the boards forming the screens 7 and one form of arrangement of the holes 8 therein. I preferably provide connections 9, 9 located adjacent the parts of the anode containing boxes farthest removed from the cathode 4, so that these connectors will not be too rapidly attacked by the electrolyte.

The anode boxes are, as shown, filled with relatively small pieces of copper so that the number of edgesexposed to the action of the electrolyte throughout'any given portion of the anode is sufficient to render the amount, of copper deposited on any given longitudinal portion of the cathode 4 substantially equal to the amount of copper deposited on other portions thereof. 7

Among other advantages in connection with the method and apparatus herein disclosed. I wish to call attention to the fact that the anode material may be replenished during the operation of the drum, that the anode material is always in close proximity to the drum without the danger of one port-ion thereof becoming substantially closer than other portions, thereby to create unevenness in the amount of deposit on the various parts of the cathode 4:, and that the screen or anode retainer 7, by reason of the even distribution of the apertures throughout the surface thereof, tends to distribute the ionic flow in the event that there should be a tendency for an excess of flow at any given portion thereof.

While I have shown and described one embodiment of my invention, and one method of practising the same, it will be understood that major changes may be made in the apparatus, and that even changes in the process may be made, without departing from the scope of my invention, which is best defined in the following claims.

Claims:

1. T he process of electrolytically depositing metal of uniform thickness, which comprises revolving a cylindrical cathode drum, while partially immersed in an electrolyte, and" while passing an electric current through a mass of relatively small pieces of metal immersed in the electrolyte as an anode, and while maintaining the general surface of the anode in a posit-ion substantially equidistant in radial plane from the surface of the cathode drum.

2. The process of electrolytically depositing metal of uniform thickness which coniprises providing anode material behind a perforate retaining screen and relatively close to the surface of the cathode, and inducing a flow of the electrolyte past the openings in the anode screen, thereby to promote evenness and uniformity of ionic flow to the adjacent cathode surface.

3. The process of electrolytically depositing metallic sheets of uniform thickness,- which comprises providing as an anode a mass of relatively small pieces of metal immersed in the electrolyte, and rotating the cathode while maintaining in substantial parallelism the surface of the cathode and the adjacent general surface of the mass of small pieces of metal forming the anode.

In testimony whereof, I have signed my name to this specification.

MATTHEW M. MERRITT. 

